Insulated conductors having fabric layers impregnated with ester gum saturants



Sept. 2, 194 s. E. BRILLHART ET AL fi fi INSULATED CONDUCTORS HAVING FABRIC LAYERS IMPREGNATED WITH ESTER GUM SATURANTS Filed June 8, 1942 CONDUCTOR INSULATION TEX TILE PLASTIC/ZED COLQRED ESTER GUM GOAT/7V6 SATURAIVT PIGMEN FED PLASTIC/ZED ES TER GUM iNVENTOI-RS S. EBR/LLHAH? A. N. GRAY Patented Sept. 2, 1947 INSULATED CONDUCTQRS HAVING FABRIC LAYERS IMPREGNATED WITH ESTER GUM SATURANTS Samuel E. Brillhart,-Lutherville, and Alvin N. Gray, Joppa, Md., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application June 8, 1942, Serial No. 446,282

This invention relates to insulated conductors and more particularly to insulated conductors comprising a layer of impregnated fibrous material and methods for producing them.

Asphalt saturants and stearine pitch have been used previously for impregnating and weatherprooflng fibrous coverings on conductors, which were subsequently coated with light-colored lacquers. However, for many purposes these materials were not satisfactory because the lacquer frequently was chipped or scraped oil, and the black color of the saturant showed through and give the product an undesirable appearance.

An object of this invention is to provide new and improved insulated conductors and more particularly to provide new and improved insulated conductors comprising a layer of impregnated fibrous material.

An insulated conductor embodying the present invention comprises a conductor, a layer of impregnated fibrous material surrounding the conductor, in which the impregnating material is a mixture of plasticized ester gums, and a coating for covering the impregnated fibrous layer which comprises a mixture of plasticized ester gums and a pigment for coloring the mixture.

Other objects and features of the invention will become apparent from the following detailed description, when read in conjunction with the accompanying drawing in which the single figure is a perspective view of an insulated conductor embodying the invention.

In the particular embodiment of the invention disclosed in the accompanying drawing, a conductor I is surrounded by a layer of insulating material ll, such as rubber or the like. A layer of fibrous material I2, which in this specific embodiment of the invention is braided cotton, surrounds the insulating layer H and is weatherproofed by being impregnated with a saturant l3 comprising a mixture of plasticized ester gums.

Ester gums are enerally defined as esters of abietic acid, but this term is usually applied to the methyl, ethyl, and glyceryl esters of this acid. One particular type of ester gums which may be used is produced by the reaction of quicklime, glycerine, and rosin oil in the presence of heat. The reaction product is probably a complex mixture of many compounds, including a large proportion of a glyceride or glycerides of abietic acid and the calcium salt of this acid. However, other ester gums or the same ester gums made by a diiierent process, having the desired properties of impregnating and weather 19 Claims. (Cl. 174-120) 2 proofing textile insulating material may be used with satisfactory results.

Blown soy bean oil is mixed with the ester gums to plasticizethe mixture and render it more suitable for impregnating purposes. The particular plasticizer used'will depend upon the results which it is desired to obtain. -While in this particular embodiment of the invention a semi-drying oil (blown soy bean oil) is used, drying or non-drying oils, as wellas many other wellknown plasticizers, may also be employed. The mixture of plasticized ester gums is heated to about 300 F. and applied to the textile layer H, which it readily impregnates at this temperature. This impregnation may be suitably accomplished by passing the textile covered conductor through a molten bath of the saturant and wiping oil the excess.

A coating 14, similar to the above-described saturant, excepting that it contains less plassicizer and, in addition, a pigment such as lithopone, for coloring the mixture, is applied over the textile layer l2. The coating l4 may form the outer coating of the insulated conductor, or may, as in this particular embodiment of the invention, provide a base on which is applied an outer coating ll: of colored cellulose lacquer.

Due to several factors, such an insulated conductor withstands mechanicalhandling particularly well without showing damage. In the first place, the semi-drying properties of the soy bean oil prevent hardening of the saturant, so that there. is no subsequent cracking of the impregnated braid. Also, the cohesiveness of the ester gum saturant holds the braid together better than the materials previously used. Lastly, the similarity of the colors of the outer lacquer coating l5 and the pigmented coating l4, produces an insulated conductor having a uniform color even though small cracks or chips may occur in the outer coating. The ester gum saturant l3 has proved to be a satisfactory substitute for the asphalt and stearine saturants previously used and is more suitable than the latter as an undercoating for colored lacquers.

Various modifications of the above-described embodiment of the-invention may be made without departing from the spirit of the invention. For example, the layer of rubber compound may be omitted entirely and the textile layer may surround the bare conductor. Several types of textiles. as well as f brous material not classed as textile, may be used in place of the braided textile layer above described. Many different types of paints and lacquers maybe employed in place of cellulose lacquer. These and other modifications will be apparent to those skilled in the art.

The ester gums and plasticizers referred to hereinabove apparently do not enter into a chemical reaction, and no substantial part of such a mixture is converted into another product. The term substantially unconverted, as used in the annexed claims, is intended to cover the unreacted mixtures of ester gums and plasticizers employed in practicing this invention.

What is claimed is:

1. An insulated conductor, which comprises a conductor, and a layer of fibrous material impregnated with a plastic mixture consisting of substantially unconverted ester gums and a plasticizer surrounding the conductor.

2. An insulated conductor, which comprises a conductor, a layer of fibrous material impregnated with a plastic mixture consisting of substantially unconverted ester gums and a plasticizer surrounding the conductor, and a coating of a plastic mixture consistin of substantially unconverted ester gums, a plasticizer and a pi ment surrounding the impregnated fibrous layer.

3. An insulated conductor, which comprises a conductor, a layer of insulating material surrounding the conductor, and a layer of fibrous material impregnated with a plastic mixture onsisting of substantially unconverted ester gums and a plasticizer surrounding the layer of insulating material.

4. An insulated conductor, which comprises a conductor, a layer or rubber composition insula tion surrounding the conductor, a layer of fibrous material impregnated with a plastic mixture consisting of substantially unconverted ester gums and a plasticizer surroundin the layer of insulation, a coating consisting of substantially unconverted ester gums, a plasticizer and a pigment covering the impregnated fibrous layer, and an outer colored cellulose lacquer covering which is similar in color to the coating therebeneath,

5. An insulated conductor, which comprises a conductor, and a layer of fibrous material impregnated with a plastic mixture consisting of substantially unconverted ester gums and blown soy bean oil surrounding the conductor.

6. An insulated conductor, which comprises a conductor, a layer 01' fibrous material impregnated with a plastic mixture consistin of sub stantially unconverted ester gums and a scmidrying oil surrounding the conductor, and plastic coating consisting of substantiaily'unconverted ester gums, a semi-drying oil and a pig ment covering the impregnated fibrous layer,

7. An insulated conductor, which comprises a conductor, a layer of fibrous material impregnated with a plastic mixture consisting of substantially unconverted ester gums and a, semidrying oil surrounding the conductor, a plastic coating consisting of substantially unconverted ester gums, blown soy bean oil and a pigment surrounding the impregnated fibrous layer, and an outer coating of paint.

8. An insulated conductor, which comprises a conductor, a layer of textile material impregmated with a plastic mixture consisting of substantially unconverted ester gums and blown soy bean oil surrounding the conductor, a plastic coating consisting of substantially unconverted ester gums, blown soy bean oil and lithopone covering the impregnated textile layer, and an outer coating of colored cellulose lacquer.

9, An insulated conductor, which comprises a conductor, a layer of insulation surrounding the conductor, a layer of fibrous material impregnated with a plastic mixture consisting of substantially unconverted ester gums and blown soy bean oil surrounding the layer of insulation, and a coating consisting of substantially unconverted ester gums, blown soy bean oil and lithopone surrounding the impregnated fibrous layer.

10, An insulated conductor, which comprises a conductor, a layer of insulation surrounding the conductor, a layer of textile material impregnated with a plastic mixture consisting of substantially unconverted ester gums and a semidrying oil surrounding the layer of insulation, a plastic coating consisting of substantially unconverted ester gums, blown soy bean oil and a pi ment surroundin the impregnated textile layer, and an outer coating of colored cellulose lacquer.

11. An insulated conductor, which comprises a conductor, a layer of rubber composition insulation surrounding the conductor, a layer of textile impregnated with a plastic mixture consisting or substantially unconverted ester gums and blown soy bean oil surrounding the layer of insulation, a coating consisting of substantially unconverted ester gums, blown soy bean oil and lithopone surrounding the impregnated textile layer, and an outer coating of cellulose lacquer.

12. An insulated conductor, which comprises a conductor, a layer of insulation surrounding the conductor, a layer of textile impregnated with a saturant consisting of substantially unconverted ester gums and a plasticizer surrounding the layer of insulation, a coating of a mixture consisting of material substantially like the saturant and a pigment surrounding the impregnated textile layer, and an outer layer of colored cellulose lacquer.

13. An insulated conductor, which comprises a conductor, a layer of rubber composition insulation surrounding the conductor, a layer of fibrous material impregnated with a saturant consisting of substantially unconverted ester gums and blown soy bean oil surrounding the layer of insulation, a coating of a mixture consisting of lithopone and a material substantially like the saturant surrounding the impregnated fibrous layer, and an outer layer of colored cellulose lacquer which is similar in color to the coating therebeneath.

l4. An insulated conductor, which comprises a conductor, a layer of vulcanized insulating com pound surrounding the conductor, and a layer of fibrous int tcrial impregnated with a weatherproof plastic mixture consisting of substantially unconverted ester gum and a plasticizer surroundin the layer of insulating compound.

15. An insulated conductor, which comprises a filamentary conductor, a sheath of vulcanized insulating compound surrounding the conductor, and a layer of textile impregnated with a weatherproof saturant consisting of substantially unconverted ester gums plasticized with blown soy bean oil urrounding the sheath.

16. An insulated conductor, which comprises a filamentary conductor, a sheath of vulcanized rubber insulating compound surrounding the conductor, and a layer of braided cotton impregnated with a weatherproof saturant consisting of substantially unconverted ester gums plasticizer! with blown soy bean oil surrounding the sheath.

17. An insulated electrical conductor, which comprises a conductor wire, an insulating jacket thereon, and thereover a tubular protective textile jacket impregnated with a plastic mixture consisting of substantially unconver ed ester gums and a plasticizer said mixture serving to adhesively unite the elements of the textile jacket to the insulating jacket and to each other whereby the conductor is caused to withstand damage by mechanical handling.

18. An insulated electrical conductor, which comprises a conducting core, a vulcanized rubber insulating jacket applied directly to said core, and directly over said insulating jacket a single tubular textile jacket impregnated with a plastic mixture consisting of substantially unconverted ester gums and a, plasticizer, said mixture having the property of setting by cooling from the molten state only to a soft, pliable, solid, adhesive state and having in its set state suilicient adhesiveness to adhesively unite the elements of the textile jacket together and to hold the textile jacket in adhesive contact with the insulating jacket whereby the conductor is caused to withstand damage by mechanical handling.

19. An insulated electrical conductor, which comprises a conductor wire, an insulating Jacket thereon, and thereover a tubular protective jacket of cotton strands impregnated with a plastic mixture consisting of substantially unconverted ester gums and a plasticizer, said mixture serving to adhesively unite the indivduai strands of the protective jacket to the insulating jacket and to each other whereby the conductor is caused to withstand damage by mechanical handling.

SAMUEL E. BRILLHART. ALVIN N. GRAY.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,833,810 Wright Nov. 24, 1931 2,096,537 Colvin Oct, 19, 1937 15 2,000,095 Pitman May 7, 1935 1,822,411 McArdle Sept. 8, 1931 2,275,583 Catlow Mar. 10, 1942 FOREIGN PATENTS 0 Number Country Date 389,816 Great Britain Mar. 17, 1933 25 pp. 1, 14. Recd. 10/29/35. Class 106-218. 

